I LOVED IT!
There were a few problems I had with the film. Besides the main characters of Elizabeth Shaw, David, Meredith Vickers, and Janek, I thought character development was poor for the other characters like Shaw's boyfriend and the two guys that ended up behind and had to stay the night (don't wanna spoil anything for those who didn't see it).
The script was good, but not great. The screenwriters Jon Spaihts and Damon Lindelof, threw a bunch of great questions at the audience related to science vs. religion and creationism, but they never gave us a concrete foundation to come up with any sort of answers. So the finale seemed incomplete for me. I'm not saying every movie has to spell everything out and give us the answers. I like movies that makes you question things and the director lets you decide what the answer is, and I think Prometheus missed the mark.
So is it a prequel to Alien or is this a stand alone (spin off on the Alien universe) sci-fi movie? It's a stand alone. Just because of the little scene at the end, doesn't make the entire movie a prequel to Alien. The two movies' themes are completely different and the tone is quite different as well.
I loved Ridley Scott's direction and the visuals were EXTRAORDINARY and GORGEOUS! Definitely a very strong contender for next year's visual effects Oscar. Even an Oscar nomination for Michael Fassbender for Best Supporting Actor?
If you haven't seen it, GO SEE IT!!